This invention relates to drawing equipment capable of describing a range of ellipses, closed curves and circles. This invention is not limited to drafting and would be a valuable aid in the textile, metal and glass industries.
Prior devices such as those disclosed in U.S. Pat. Nos. 4,170,824 and 4,150,487 have been capable of describing elliptical shapes but they have not been wholly satisfactory.
This invention utilizes a novel principle which produces a greater variety of curves; can describe truer ellipses, circles and symmetrical curves; is far more simpler and more economical to manufacture; requires no particular user skill and is more adaptable to common drawing needs.